Sound-concentrator for telephone-transmitters



E. TAYLOR. SOUND CONCENTR ATOR FOR TELEPHONE TRANSMITTEBS.

APPLICATION FILED SEPT-23. 1919- I I I Patented May 1%,11921.

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ZELMEB EVEB'I. TAYLQR, O15 LOUGOTJTEE, DJDMNA.

SQfiND-CONCENTRATOE F03, TELEPHONE-TEANSMTTEEfi.

Specification of Letters Patent. Patented May it}, 1921i,

Application filed September 23, 1919. serial No. 325.7629.

To all whom it maconcem:

Be it known that ,ELMER Evnn'r Tarron, a citizen of the United States,residing at Loogootee, in the county of Martin and State of Indiana,have invented a new and.

such as a small battery, and connectionswhereby the whole instrument isindividual 'to the deaf person, the battery and transmitter beingcarried on the person in convenient position to be reached by soundwaves and the receiver being at one-end of a flexible cord connected atthe other end to the transmitter so that the receiver may beconveniently placed at the ear of the wearer. Such instruments are,however, subject to distracting influences but such distractingcondltions are eliminated bythe invention which comprises a. cap to fitsnugly over the sound receiving mouthpiece of the transmitter. The caphas a face portion with a sound transmitting" opening therein similar nexterior contour to an ordinary transmltter mouthpiece, but of a depthto space the sound receiving-opening a: suitable dlstance from themouthpiece ofthe transmitter to which the-cap is applied. The interiorof the cap is provided with a concentrating cavity of a nature todirectsound which might otherwise confuse the. impingement of the receivedsound onto the diaphragm of the transmitter so that such formerlyconfusin sounds are all reflected and diverted direct y onto. thatportion of the transmitter diaphragm most susceptible to the receivedsounds. The result is that the received sound is clarified and so mademore distinct and is also concentrated onto the central portion of thetransmitter diaphragm in such manner as to greatly amplify or magnifythe received sound, with the further result that the reception of thesound is made clearer and more intense than has heretofore been thecase.

The invention will .be best understood from a consideration of thefollowing detalled descrlption taken in connection with the accompanyingdrawing forming part of this specification, with the understanding,

however, that the invention is not confined to any strict conformitywith the showing of the drawing, but may be changed and modified so longas-such changes and modifications mark no material departure from thesalient features of the inventionas expressed in the appended claims. 1][n the drawing Figure 1 is a perspective view of a form of localtelephone for use by a deaf person, with the invention applied.

Fig. 2 is a side elevation of the transmitter with some parts insection.

Fig. 3 is an elevation of the sound concentrator as viewed from the rearface.

Referring to the drawing, there is shown a telephone transmitter 1 whichmay be of any suitable type such as is adapted for use in connectionwith instruments for aiding hearing by the deaf The transmitter ismounted upon a suitable battery 2, of which only the casing is shown inthe drawing, for neither the interior construction of the transmitternor the interior construction of the battery is illustrated in thedrawing, these parts following .the usual custom and in their detailsforming no part of the invention. The transmitter 1 has a mouth pieceportion 3 with a ledge d and shoulder 5 about its periphery, theconstruction of these parts being such' as is customarily employed andtherefore requiring no particu-.

lar description. The transmitter 1 is provided with a loop 6, wherebythe transmitter with the battery 2 may be fastened to the clothing ofthe wearer, preferably in front of the chest as a convenient locationfor receivin sound waves from'a person talking to t e wearer of thetransmitter. ast to the transmitter is one end of a flexible cord 7 theother end of which is attached to a telephone receiver 8 adapted to beplaced against the ear of "the user. The

receiver 8 is provided with suitable switch mechanism of which amanipulating fingerpiece 9 only is shown, for the switch may be of'known construction and requires no special description, nor need itsspecific construction be indicated in the drawing for an understandingof the invention. The finger-piece 9 is moved in one direction to coupleup the battery, transmitter and receiver for listening purposes, and ismoved in the other directlon to cut out the battery flected by the walls16, 18 and 19 in paths when the instrument is not in use.

The instrument so far described is of commercial form and is found uponthe market and is especially adapted for the application of theinvention without any change whatever or necessitating the use of toolsor the modification of the invention or instrument.

The invention is best shown in Figs. 2 and 3 which illustrate sectionaland interior views respectively, while the exterior configuration of theinvention best appears in The invention comprises a cap 10 of opencylindrical form at one end as shown at 11, and terminating in acircumferential flange 12 shaped to snugly fit over the ledge 1.

From the flange 12 the exterior of the cap 10 is frusto-conical as shownat 13, the eX- terior wall being ultimately returned upon itself andtoward the flange 12 with the return portion approaching thelongitudinal axis of the cap to provide an inturned conical mouthpieceor duct 14 with a central opening'or passage 15 for sound waves, thepassage 15 providing for the entrance of the sound waves into theinterior of the 'cap 10. The mouthpiece 3 of the transmitter bulgesoutwardly from the shoulder 5 for a short distance and that wall of thecap 10 toward the'flange 12 is thickened to provide a cylindrical innerwall 16 of an axial depth approaching about half, or a little more, ofthe full depth of the interior of the cap 10,

where the cap when applied to the transmitter mouthpiece defines acavity 17.

From the outer margin of the wall 16 the interiorof the cap is formedwith a conical .wall 18Mreceding from the flange 12 and wall .16 toabout half the distance between the wall; 16, and the mouthpiece opening15 and fromsuchpoint the cavity 17 is formed ,,with another wall 19 ofconical. [form approaching the mouthpiece ofv the transmitter ,andthelongitudinal central axis of the cap until, it,reaches the,opening.;15.,The cavity 17 therefore is in p the main of cylindrical conformationwith; a portion immediately det id g 0 ba k f the s u r e i ,face ,ofthe cap ,,o'f reversely conical'shape ,2 with the small endof the outer.conical wall,

and the largejend of the inner conical'walll the point of,greatestdistance of the cavity 17 from the j mouthpiece of thetransmitter.

merging? andfithere definin The result of such construction is that,sound waves reaching the transmitter are directed through the Opening15 into the cavity 17 directly toward the regular sound-receivingdiaphragm of the transmitter. Or-

, clinarily but a relatively small part of the sound waves is caught bysuch diaphragm r and by far the larger portion is lost. With the cap 10in place all the sound waves entering through the passage 15 eitherdirectly reach the transmit-ter diaphragm or are recausing the soundwaves to ultimately strike the diaphragm of the transmitter. Thequantityof sound waves so becoming effec-' tive include all or nearlyall the energy represented by the originally projected sound waves andthe intensity of the received sound and the energy transmitted to thetelephone receiver at the ear of the hearer is greatly increased.Because of this the user is enabled to plainly hear the transmittedsounds because of their loudness while the direction of reflection ortransmission of the sounds in the cavity or chamber 17 preventsinterference of. these sounds and hence a clarity of the received soundgreatly exceeding the usual reception of sound where the sound appearsweak to the deaf person and there is loss of clearness due to theinterfer-- ence of cross waves of sound caused by obstructingreflections of the sound in the usual forms of amplifiers.

The angular relation of the walls 18 and 19 to each other and to thecylindrical wall 16, and-also their relation to the transmitterdiaphragm, are important as affecting the clearness and intensity of thesounds reachin the ear of the listener. 1

The walls 18 and 19 join at an obtuse angle to each other and the wall18 joins the wall- 16 at an obtuse angle and as the walls are circularthe sound waves reaching them that the invention is particularlydesigned and for which it is particularly adapted.

. I The instrument referred to employs a'tele- [phone transmitter towhich the attachment ofjthe inventionis applied, and a telephone 1receiver to, be held to the ear of the user. As

theinvention is useful for both the instrument for aiding the deaf tohear and the usual commercial telephone, the term telephone transmitterhas been used in the 'description and claims as generic enough to 3apply to such and to other acoustical instruments.

I What is claimed is 1. A telephone instrument provided with a sourceofelectric energy, a microphonie telephone transmitter carried thereby, atelephone receiver connected to the transmitter,

and a soundclarifying and-amplifying cap adapted to fit snugly over thesoundreceiving mouth-piece of the transmitter and producing a cavity inconjunction therewith, with a concentrating mouth-piece directed towardthe transmitter diaphragm and shaped to form an inturned conicalmouthpiece opening into a doubly conical cavity receding from thetransmitter diaphragm and then approaching the diaphragm with the wallsshaped to accumulate and direct the reflections of sound against thecentral portion of the transmitter diaphragm.

2. A sound concentrator for telephone instruments, comprising a cap forthe mouthpiece end of the transmitter having a central soundtransmitting opening over and approximately of the same size as that ofthe transmitter to snugly embrace the transmitter casing, with the depthof the cap such as to space the sound receiving face of the cap awayfrom the transmitter by about approximately half the full depth of thecap and said cap having an interior cylindrical wall surrounding thetransmitter mouthpiece with the outer end of the cap provided withtrusto conical inner walls meeting intermediately between thecylindrical wall and there merging, whereby the inner walls of the capconstitute reflecting surfaces for sound' waves directing said Wavestoward and concentrating them onto the central portion of the receiverdiaphragm.

3. In a soundconcentrator. for telephone transmitters and other similaracoustical instruments, a cap for application to the sound receivinghead of the instrument and having the head of the cap remotefrom thatapplied to the instrument provided with an opening for the admission ofsound, with the size of the cap related to the size of the head of theinstrument to form a cavity of substantially the diameter of the soundreceiving head of the instrument and of a depth to provide a chamber,with said chamber having cylindrical side walls and end wall in whichthe sound receiving opening is located and said end of the head betweenthe cylindrical side walls and the outer end of the head having obtuselyjoined conical walls facing toward the head of the instrument with. theouter conical wall extending from the sound receiving opening at theouter end of the cap.

In testimony that I claim the foregoing as my own, I have hereto aflixedmy signature.

ELMER nvnn'r TAYLOR.

